What is the atomic mass of an element that has 6 protons, 7 neutrons, and 6 electrons?

Naturally occurring europium (Eu) consists of two isotopes was a mass of 151 and 153 . Europium-151 has an abundance of 48.03% a

Minchanka [31]

Answer:

151.94 u

Explanation:

The atomic mass of Eu is the weighted average of the atomic masses of its isotopes.

We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its percent abundance).

The atomic masses of Eu-151 and Eu-153 are 150.92 u and 152.92 u, respectively.

Set up a table for easy calculation.

0.4803 × 150.92 u = 72.472 u

0.5197 × 152.92 u = 79.473 u

TOTAL = 151.94 u

6 0

3 years ago

Read 2 more answers

A proposed mechanism for the reaction of NO2 and CO is

Novosadov [1.4K]

Answer:

a.

1. NO2(g): Reactant.

2. CO(g): Reactant.

3. NO3(g): Intermediate.

4. CO2(g): Product.

5. NO(g): Product.

b. See attached picture.

Explanation:

Hello,

a. In this case, given the reactions, we can identify each species as:

1. NO2(g): Reactant because it remains at the left side in the overall reaction.

2. CO(g): Reactant because it remains at the left side in the overall reaction.

3. NO3(g): Intermediate because it is a product in the step 1 and a reactant in step 2, for that reason it is not present in the overall reaction.

4. CO2(g): Product because it remains at the right side in the overall reaction.

5. NO(g): Product because it remains at the right side in the overall reaction.

b. In this case, given that the first step is slow and endothermic, it has a high activation energy and the products will have more energy than the reactants, for that reason the final energy is above the initial point. Moreover, since the second step is fast and exothermic, it has a low activation energy and the products will have less energy than the reactants, for that reason, the reaction coordinate diagram is shown on the attached file.

Regards.

8 0

3 years ago

Can some one help I'm lost iam being timed:( Show using two conversion factors how you would convert from 0.020 kg into mg

dezoksy [38]

Answer:

20000 Mg

Explanation:

5 0

2 years ago

Citric acid (C6H8O7) is a triprotic acid (It has 3 protons that can dissociate when dissolved) found naturally in lemon juice, a

Gnesinka [82]

Answer: The molarity of citric acid that is commercially available lemon juice is 0.416 M

Explanation:

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $C_6H_8O_7$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=3\\M_1=?M\\V_1=20.00mL\\n_2=1\\M_2=1.751M\\V_2=14.26mL$

Putting values in above equation, we get:

$3\times M_1\times 20.00=1\times 1.751\times 14.26\\\\M_1=\frac{1\times 1.751\times 14.26}{3\times 20.00}=0.416M$

Hence, the molarity of citric acid that is commercially available lemon juice is 0.416 M

4 0

2 years ago

When will diffusion slow down

scZoUnD [109]

Answer:

Exchange across cell membranes - diffusion. The higher the concentration gradient, the faster the rate of facilitated diffusion, up to a point. As equilibrium is reached the concentration gradient is much lower because the difference in concentrations is very small so the rate of facilitated diffusion will slow down and level off.

Explanation:

6 0

3 years ago